The present invention relates to a printer provided with an automatic memory initializing function.
A printer is known, which is of type in which a user can select respective initial states of various functions of the printer, after a power switch of the printer has been turned on, but before the actual printing operation is executed. The various functions include the following examples:
(a) Selectively setting an interface between the printer and a host computer or the like to which the printer is connected. For instance, function selectively setting either one of a parallel interface and a serial interface;
(b) Selectively setting a dot-arrangement which determines if characters to be printed are ones for a draft or ones of high quality;
(c) Selectively setting a pitch of characters to be printed;
(d) Selectively setting a pitch of lines to be printed;
(e) Selectively setting a paper length; and
(f) Selectively setting nationalityclassified character codes.
The above-described various functions have conventionally been set by multi-bit switches called "DIP", switches. By the way, the functions of the printer have been diversifying increasingly. The following problems arise attendant upon the diversification of the functions. As the number of functions set by the switches increases, the number of the bits of the DIP switch cannot but increase. As a result, the manipulation of the printer has been made troublesome and cumbersome. In addition, a DIP switch having a high bit number is high in cost, rendering the printer per se expensive.
In recent years, a printer having incorporated therein a nonvolatile RAM (random-access memory) in place of the DIP switches has been developed in order to cope with the above-discussed problem. In the printer, various functions are stored in the nonvolatile RAM, and functions of the printer are set on the basis of the stored functions. The functions of the printer can be modified by rewriting the contents of the nonvolatile RAM by manipulation of an operating panel or the like.
There are cases where it is required to initialize the currently used entire areas of the nonvolatile RAM before the use thereof. To this end, the printer is provided with an initializing function. The contents of the memory initialized by the initializing function are called "factory default" conditions.
The cases where it is required to initialize the nonvolatile RAM include the following ones:
(1) Case where a power switch is turned on at the production stage in a factory to cause electric current to first flow through a printed circuit board; PA0 (2) Case just before shipment of the printer produced at the factory; PA0 (3) Case where a user desires to return to "factory default"; PA0 (4) Case where the contents in the nonvolatile RAM have been volatilized due to occurrence of any abnormality; and PA0 (5) Case where a control unit is replaced by a new one in order to up grade the functions of the printer.
The above case (1) is a case where electric current is caused to pass, for the first time, through the printed circuit board to which components are mounted actually. Since, in this case, the contents of the nonvolatile RAM are undefined, it is necessary to initialize the nonvolatile RAM.
The above case (2) is a case where the contents of the nonvolatile RAM have been rewritten due to delivery adjustment or the like. In this case, it is required to define the stored contents of the nonvolatile RAM at the time of shipment.
The above case where (3) is a case the printer's using environment is altered, such as, for example, a case where a user changes the host computer to which the printer is connected.
In the above case (4), it is a matter of course that the various functions of the printer are required to be set again in the nonvolatile RAM. Accordingly, it is necessary to first initialize the nonvolatile RAM.
The above case (5) is a case where, in a printer controlled by a CPU (central processing unit), a ROM (read-only memory) having stored therein a control program and control codes for the control program is replaced by another one. For instance, a printer, even one which has once been shipped, can be used as a printer upgraded in function, by replacing the currently used ROM with a new one having incorporated therein new functions. Since, in this case, areas within the nonvolatile RAM, which are utilized for the new functions, are ones which have not conventionally been used, the contents of the areas are undefined. Accordingly, when the ROM having stored therein the control codes is replaced by new one, it is necessary to carry out such initializing operation as to transfer initializing data stored in the new ROM to the nonvolatile RAM. Should the printer be operated without of the initializing operation of the nonvolatile RAM, the printer would perform unforeseen operation.
The above-mentioned initialization of the memory is not usually carried out frequently and, accordingly, must not easily be carried out by ordinary users. For this reason, the operation method of the memory initialization is generally made complicated. In case of, for example, an operating panel having four manipulating keys, the memory initialization is carried out by pushing two keys simultaneously. In this manner, the initializing operation per se is made complicated. As a result, there is a high possibility that one forgets the initializing operation. This becomes a problem of the printer of the type in which the functions are set by and stored in the nonvolatile RAM.